Introduction
Chronic obstructive pulmonary disease (COPD) is characterized by progressive and irreversible airflow obstruction, and is associated with high morbidity and mortality [
1]. Globally, COPD is the fourth leading cause of death and is projected to be the seventh highest contributor to the total disability-adjusted life years (DALYs) lost by the year 2030 [
2,
3]; in addition, it ranks as the fourth leading cause of disability-adjusted life years in China [
4]. Currently, COPD is a major public health problem owing to its detrimental effect on the health status of patients.
COPD is a chronic respiratory disease which is associated with multiple comorbidities including cardiovascular disease, skeletal muscle dysfunction, metabolic syndrome, osteoporosis, depression, and lung cancer [
1]. However, depression is one of the most common comorbid conditions in patients with COPD. Moreover, COPD patients are more commonly affected by depression as compared to patients with other chronic conditions [
2]. The prevalence of depression in people with COPD was shown to be twofold higher than that in people without COPD [
5]. Owing to the considerable overlap between the somatic symptoms of depression and symptoms of COPD, the presence of this mental disease is liable to be unrecognized by COPD patients and more likely to be missed by their physicians as compared to patients with other comorbidities or depression alone [
6]. Moreover, the stigma of mental ill-health can prevent people who may be suffering from depression from seeking care from a psychologist. Owing to these factors, depression may remain undetected, undertreated, or even untreated in patients with COPD. It can in turn lead to deterioration of COPD, since it may reduce patient compliance with COPD treatment. A meta-analysis of studies revealed that COPD patients with depression exhibit lower treatment adherence [
7] and that depression can worsen the symptoms of COPD and make it harder to improve self-efficacy; in addition, depression was shown to increase the incidence of acute exacerbation and hospitalization [
8,
9], impair the patient’s quality of life, worsen the prognosis [
2], and lead to higher mortality [
10]. Therefore, intervention for depression may play an important role in the management of patients with COPD. The combination of COPD and depression is projected to cause significant health problems in the next decade [
5].
Studies have shown that identification and treatment of depressive symptoms in patients with COPD may have a favorable effect on mood, exercise tolerance, quality of life, and related symptoms [
11‐
15]. Consequently, there is a need to identify suitable interventions to help COPD patients to manage depressive symptoms and to reduce the burden of COPD. The National Institute for Health and Care Excellence (NICE) recommends psychological and pharmacological therapies for treatment of depression based on solid systematic reviews or valuable experiences [
16]. However, robust evidence of the efficacy of antidepressants in ameliorating depression or in improving the symptoms associated with COPD is largely lacking [
17]. Moreover, some COPD patients may refuse pharmacological treatment owing to concerns pertaining to the side effect of antidepressant drugs. Recent studies have shown that pulmonary rehabilitation program can reduce the severity of depressive symptoms in COPD patients regardless of the disease stage, patients’ gender, age, or education level [
11,
12]. Psychological interventions, such as cognitive behavioral therapy (CBT), have been widely used in depressed COPD patients; individualized or group CBT was shown to ameliorate depressive symptoms and prevent aggravation of COPD [
11,
12]. Music therapy has been subjected to substantial research especially for treatment of chronic conditions, and it is one of the complementary or alternative therapies that belong to the category of “mind-body medicine”[
18]. Several studies have documented its beneficial effects in patients with chronic diseases [
19,
20]. Music therapy was shown to induce clinically significant changes in mood and symptoms of COPD patients [
21]. Singing is an active music therapy and is widely used for treatment of physiological and psychological disorders [
20,
22‐
25]. The IMPRESS British Thoracic Society Guidelines for Pulmonary Rehabilitation consider singing therapy as an adjuvant therapy [
26]. Moreover, singing therapy may potentially improve physical health-related life quality and alleviate anxiety without any obvious side effects; however, conclusive evidence of the effect of singing therapy on clinical symptoms and the quality of life of COPD patients is yet to be obtained [
27]. In a pilot study, singing therapy was shown to enhance lung function, reduce anxiety, and boost self-esteem of patients with COPD; however, the improvement in quality of life was not statistically significant [
28]. Two previous studies suggest that singing in group improves the quality of life, ameliorates anxiety levels, and induces a feeling of well-being and social support in patients with chronic respiratory diseases [
24,
25]. A cohort of COPD patients who were recruited to a new community-based singing group, which met weekly for over 1 year, revealed significant reduction in Hospital Anxiety and Depression Scale (HADS) anxiety score but not in HADS depression score (HADS-D) after 1 year [
29].
Reports have shown that music facilitates expression of emotions among participants [
30], which may help uplift the mood. In addition, singing is a particular type of respiratory exercise that demands repetitive diaphragm contractions, followed by sustained contractions of expiratory muscles against semi-closed vocal cords during expirations. This training involving breathing control and respiratory muscle exertion may potentially improve the pulmonary function and help alleviate symptoms of COPD [
31]. It is noteworthy that depression showed a strong correlation with COPD symptoms and quality of life. COPD patients with depression experience more frequent exacerbations, and have higher health care resource utilization and reduced health-related quality of life [
8,
9]. Depression is an independent risk factor for COPD [
1], and depression influences treatment compliance and worsens the condition [
7]. Therefore, it is particularly important to improve depressive symptoms in COPD patients. However, no studies have investigated the effect of music therapy on depressive symptoms and the quality of life of patients with stable COPD and comorbid depression. We hypothesized that group singing practice could decrease depressive symptoms and improve the quality of life of these patients.
Discussion
Our results indicate a beneficial effect of group singing therapy on mild to severe COPD following depression in stable clinical conditions, not only with respect to alleviation of depressive symptoms, but also with respect to improvement in the quality of life. However, no significant effect was observed in the control group.
The results of this study suggest that group singing therapy may alleviate depression in patients with COPD. Our findings are not consistent with those of other studies [
24,
25], which showed that singing therapy has no obvious effect in improving depression but that it relieves anxiety. The difference may be attributable to different song types. In this study, we chose the folk, classical, familiar, and happy songs, which are easy to learn and may have an uplifting effect. Studies have shown that singing of songs with cheerful rhythm makes people feel excited and modulates brain cortex, limbic system, brainstem reticular formation, endocrine system, and nervous system [
38]. It was also shown that singing can be a joyful and uplifting experience for participants owing to generation of a sense of positive mood, happiness, and enjoyment [
23,
39]. However, no change in depressive symptoms was observed in the control group, which suggests that routine health education had limited impact on the psychological health of COPD patients. The presence of the symptoms of dyspnea or depression in COPD patients is more likely to result in social isolation and loneliness [
9]. Although the equal amount of attention was given to the control group by experience sharing, the communication opportunity provided by the group singing therapy may be more positive and the subjects were likely to express their active emotions. For these reasons, group singing therapy could ease the depression of COPD patients.
As there is no cure for COPD, a major goal of treatment is to improve health-related quality of life in these patients. Mood disorders, lower levels of exercise tolerance, and dyspnea were shown to affect the quality of life and health status of COPD patients [
12]. In addition, a recent study showed a significant negative association between dyspnea and health status of COPD patients [
40]. In the experiment group, no significant differences were observed at the 1-month time-point, which may be attributable to the short duration of intervention. However, a significant downward trend was observed at the 3-month and 6-month time-points; the participants benefited from the intervention as it provided an environment that was conducive to sharing of interests and experiences. Moreover, the breathing exercises, vocal exercises, and singing exercises also expand the lung capacity, increase alveolar ventilation, reduce residual volume, and increase the strength of lower chest muscles, diaphragm, and abdominal muscles [
38]; moreover, this increases the ability for clearance of sputum and activity endurance, and relieve the symptoms of cough and dyspnea [
25,
41]. In the control group, CCQ scores at the 1-month time-point showed a downward tendency; however, at the 3-month and 6-month time-points, the CCQ scores showed a significant upward trend. These results indicate that routine health education may improve quality of life [
42], but this improvement is not maintained for a long time; a major reason might be associated with depression, which may lead to poor adherence to exercise [
7]. COPD patients with depressive symptoms often develop a considerable degree of hopelessness and pessimism [
6]. Consequently, this makes it difficult for patients to develop self-management ability and improve the quality of their life.
Our findings have shown that group singing therapy can reduce symptoms of depression and improve the quality of life of patients with stable COPD. This may be attributable to the several factors. All participants in this study were older than 55 years; most of them were retired and had much free time to actively participate in the study. Moreover, the participants had a history COPD since approximately 10 years; therefore, they were motivated to control the disease. Although this was a fairly representative sample of COPD patients, certain categories of patients may have been missed due to the relatively small sample size. Besides, due efforts were made during the questionnaire survey to minimize the possibility of response bias. For example, the word “depression” was not used in the HADS-D questionnaire to prevent the participants from guessing the purpose of the study.
Strengths and limitations
The study provided a direct evidence of the beneficial effect of group singing therapy on COPD patients with depression for the first time. Considering the high prevalence and low detection rate of depression among COPD patients, our study provides a beneficial and convenient therapy for COPD patients both for alleviating depression and for improving the quality of life. There are several advantages of singing: (1) is a joyful and interesting task and should be easy for patients with COPD to continually engage in the therapy; (2) has no obvious side effects, is of low-cost intervention, and is easy to be carried out for free; (3) helps in exercising the respiratory function, improves vital capacity and cardiac-pulmonary function, and is well accepted by patients with COPD; and (4) inspires confidence and love for life.
However, there are several limitations of the study. The main limitation is that patients with very severe COPD were not included. It remains unknown whether patients with severe disease can tolerate group singing therapy and whether singing therapy interventions could offer benefit for these patients. Second, this study lasted for only 6 months and it is not known whether the results noted here could be maintained over time. Third, detailed data pertaining to treatment adherence were not collected as there are no appropriate rating scales.
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